import java.util.Scanner;
public class test {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int i =2;
        for(;i<=n/2;i++){
            if(n%i==0){
                break;
            }
    }
        if(i>n/2) {
            System.out.println(n+"是素数");
        }
    }
}
